Advertising medium



Dec. 2, 1941- c. F. ENGERT ET AL 2,264,629

ADVERTISING MEDIUM Filed Feb. 26, 1940 2 Sheets-Sheet l I] INVENTOR/Lt VCasper]? E7zge i9 4 /5 BY ZQZberZ a5 5e/zmazzi Dec. 2, 1941. I

C. F. ENGERT ET AL ADVERTISING MEDIUM Filed Feb. 26, 1940 2 Sheets-Sheet2 BY (ZZberZ'G- INVENTOR. 671

/L/ ATTORNEY.

Patented Dec. 2, 1941 ADVERTISING MEDIUM Caspar F. Engert, Chicago, andAlbert G. Schmidt, Park Ridge, Ill.

Application February 26, 1940, Serial No. 320,872

5 Claims.

This invention relates to a new and improved type of advertisingmaterial or medium and to a new and improved method for the manufacturethereof. The invention is concerned more particularly with anadvertising medium and a method ofmaking an advertising medium in whichan advertising indicia or design is carried on the face or front surfaceof a flexible sheet material which contains on its rear surface acoating of a pressure sensitive adhesive of such character that theadvertising medium is adapted to be attached and is readily removablefrom plane surfaces.

An advertising medium of this general character has heretofore beenmanufactured from a base material sold under the trade name of Lexide,which comprises paper impregnated with latex. Certain coatings wereapplied to the face of the base material to facilitate printing anadvertising indicia or design thereon and a pressure sensitive adhesivecovered with holland cloth served as a coating on the rear face of thebase material.

In manufacturing such a material, the pressure sensitive adhesivecoating was applied by calendering machines. The methods used inapplying this coating have been such that it has been impractical toprint the design on the base material first and to thereafter coat thebase material with the pressure sensitive adhesive by the calenderingprocess.

This method of applying the coating of pressure sensitive adhesive tothe, base material prior to printing has had a number of disadvantages.For instance, in many cases it is desirable to print a varied coloreddesign on the face of the material and several printing operations arerequired with intermediate drying between each printing. The nature ofthe pressure sensitive adhesive coated material is such that the dryingstep between the printing operations often causes shrinkage of thematerial so that the second printed design is not in register with thefirst. This often results in a product which is not acceptable to thetrade and must be discarded. The net result is a Waste of material andan increase in the cost of the process and the product. The printingoperation by methods heretofore used in connection with such pressuresensitive adhesive coated material has also been relatively slow, partlybecause of the increased bulk of the material due to the adhesivethereon, and partly because of the necessity for printing the materialin such a way a to avoid shrinkage as much as possible.

The method heretofore used of applying the pressure sensitive adhesivecoating prior to printing the design has also had the undesirablefeature that an improperly printed or poorly printed design which had tobe discarded represented a loss not only of the base material but alsoof the pressure sensitive adhesive, and hence, from the economic pointof view such a process has left much to be desired.

One of the further problems which has arisen in connection withadvertising display materials of this type is the formation of bulgesdue to entrapped air or air pockets when the material is applied to asupporting surface such a a wall, mirror, or the like. With the largeradvertising displays, it is extremely difficult to avoid the formationof such air pockets which give rise to undesirable and unbecoming bulgesand make the posting of the display more difficult and time consuming.

Another problem which arises in connection with advertising indiciacontaining a pressure sensitive adhesive is concerned with the removalof the covering from the pressure sensitive adhesive when the poster orplacard is about to be applied. As previously indicated, a covering suchas holland cloth is applied over the pressure sensitive adhesive inorder to protect it and to keep it from sticking to other objects beforeuse. As a general rule the longer the pressure sensitive adhesiveremains in contact with the protective covering the greater is its tackor adhesive power so that the separation of the covering is sometimesrather difficult. This is particularly true where the base material onwhich the advertising matter is printed and to which the pressuresensitive adhesive is applied is made of paper, because the paper is aptto tear or split when the protective covering is separated therefrom.Tearing or splitting is not so likely to occur with base materials suchas Lexide but there is still a problem of separating the protectivecovering from the pressure sensitive adhesive coated on the Lexidebecause as previously pointed out, according to present methods ofmaking such material the entire surface of the material is coated withadhesive.

With the foregoing in mind, one of the objects of the present inventionhas been to prepare an advertising medium which is an improvement uponthe type of advertising medium previously described and which i freefrom the disadvantages of the aforesaid type of advertising medium. Tothe accomplishment of this object a feature of this invention provides anew type of pressure sensitive adhesive coating in which the pressuresensitive adhesive is applied in the form of a spotted or spaced designof such character that air is free to escape in the spaces in theadhesive pattern, thereby preventing the formation of bulges when thematerial is posted.

A further object of this invention is to provide a new and improved typeof advertising medium made from a base material having a pressuresensitive adhesive thereon characterized by the feature that the basematerial containing the adhesive is readily removable from a protectivecovering or from any support to which it is attached.

Still a further object of the invention is to provide a new and improvedtype of advertising medium of the character described in which the basematerial is made of paper containing a pressure sensitive adhesivecharacterized by the feature that the paper containing the adhesive maybe readily separated from a protective covering such as holland cloth orfrom a support without tearing.

Another object of this invention has been to provide a new sequence ofoperations in preparingadvertising materials of the character describedand a new method of applying the pressure sensitive adhesive whereby thedesign is printed on the base material prior to the application of theadhesive and the difficulties heretofore attendant proper registry ofthe design as well as the waste involved in the procedures heretoforeused are avoided while at the same time the speed of'the printingoperation is increased and substantial economies are effected. Theaccomplishment of this object has been attained by printing the designon the base material before applying the pressure sensitive adhesivethereto and by applying the pressure sensitive adhesive to the rear ofthe base material by means of a stencil having, let us say, a pattern ofuniformly spaced small openings therein.

This method of applying the pressure sensitive adhesive through astencil after the design has been printed on the base material has anumber of important advantages. In the first place, it makes it possiblefor the printer to apply the pressure sensitive adhesive coating,whereas heretofore because of the calendering operation involved it hasbeen necessary in practice to have the adhesive coating applied by arubber coater' especially equipped for the purpose. Secondly, a defectin the printing results only in a waste of the base material, whereasheretofore the pressure sensitive adhesive coating has also been a partof the waste. 'I'hirdly, the rate of printing is increased by thepresent invention as compared to methods heretofore employed. Thus, theprinting operation may be as much as 30% faster when preparing printedadvertising materials in accordance with this invention. Fourthly, theproblems of shrinkage and improper registry due to the pressure sensitive adhesive no longer exist because the pressure-sensitive adhesive isno longer present on the material during the printing operation.

. The spotteddesign of adhesive serves the full purpose of the formersolid coating and additionally prevents the formation of air pockets andbulges which interfere with the usefulness of the product. Basematerials such aspaper may now be used in accordance with this inventionto produce advertising displays of superior quality. According to afeature of the invention the adhesive pattern is applied to the basematerial in such a manner that at least one corner portion of the basematerial is free of adhesive thereby permitting the ready separation ofthe adhesively coated base material from holland cloth or otherprotective covering or from a support to which the advertising displayis attached. This feature of the invention makes it possible to usepaper as the base material without danger of tearing.

Other features and advantages of the invention will be apparent byreference to the accompanying drawings, in which:

Figure 1 represents the front face of an advertising material bearing aprinted design;

Figure 2 represents the rear face of the same material prior to theapplication of a pressure sensitive adhesive coating by a stencilingoperation;

Figure 3 represents the material of Figure 2 after a spotted design ofpressure sensitive adhesive has been applied to the rear face thereof bya stenciling operation;

Figure 4 represents the same material with a covering of holland clothor other suitable material over the pressure sensitive adhesive andpartially stripped therefrom; I

Figure 5 illustrates diagrammatically the manner in which the pressuresensitive adhesive is applied to the base material of the advertisingmedium by a stenciling operation;

Figure 6 is a view in perspective of the stenciling operation forapplying the pressure sensitive adhesive illustrated in Figure 5;

Figure 7 is a side sectional View showing the manner in which theadvertising material is applied to a wall or other plane surface;

Figure 8 illustrates a method of practicing the invention in which anumber of displays are printed simultaneously;

Figure 9 illustrates a method of forming the adhesive pattern for diecutting in a predetermined manner when the invention is practised as inFigure 8;

Figure 10 illustrates a display medium prepared as in Figure 9;

Figures 11 and 12 illustrate modified types of adhesive patterns whichmay be used in ac-- cordance with the invention.

Generally stated, the method of the present invention comprises thefollowing steps: (1) printing an advertising indicia or design on asuitable base material which may be a flexible rubber impregnatedmaterial such as Lexide or a paper of suitable texture, and (2) applyinga pressuresensitive adhesive to said base material by a stencilingoperation after the design has been printed.-

, Figure 1 illustrates a printed advertising indicia 2, which has beenapplied to one face of a suitable base material -4. At the time thisprinted indicia is applied to base material 4, the

opposite face 6 of the material 4 contains no pressure sensitiveadhesive, as shown by Figure 2. Once the printing operation is complete,however, a pressure sensitive adhesive is applied to face 6 by means ofa stencil and this may be accomplished by the use of a ,mechanicalstenciling machine or a manually operated stenciling machine consistingof a perforated plate or screen havingopenings therein of the desiredsize and shape and provided with a squeegee or equivalent device forcausing the pressure sensitive adhesive to be pressed through theopenings in the stencil.

It might be expected that the application of an adhesive in this mannerwould be difIicult because of the tendency of any adhesive to clog. theopenings in the stencil, but the practice of the invention hasdemonstrated that such is not the case. a pressure sensitive adhesivespotted design 8. on the rear surface thereof as shown in Figure 3.

The adhesive squares may be,,say, 0.2 inchsquare with the distance fromthe center line of the spaces about 0.25 inch, or they may be, 0.25 inchsquare with 1 5 inch between the centers of. the spaces. It will beunderstood of course that this design may be of a different pattern.Thus, the adhesive spots may be triangular, rectangular, parallelogram,round or other shape. They may also be relatively smaller or relativelylarger. They may, if desired, be in the form of small dots. The nature,amount and spacing of the pressure sensitive adhesive should be such asto substantially avoid the formation of entrapped air and the attendantbulges caused thereby.

In many instances, although not in every case, it will be found to bedesirable to cover the spotted adhesive design with holland cloth H] orother suitable type of covering material such as illustrated in Figure4. This is accomplished merely by applying the holland cloth or othersuitable material over the spotted pressure sensitive adhesive withpressure sufii'cient to cause adherence between the holland cloth andthe adhesive. The resultant material may then be shipped in flat or rollform. When the material isready for use the holland cloth is strippedoff and the rear surface of the material is pressed against a wall [2,or other surface, as shown in Figure 7, so that the spotted design isintermediate between the base material and the wall.

The general method of applying the adhesive to the base material isillustrated by Figures 5 and 6. As. shown, the pressure sensitiveadhesive is applied by placing the base material 4 bearing printeddesign 2 beneath a stencil or perforated screen 14 with th rear surface6 of the base material in contact or in close proximity to the stenciland the lower surface bearing the printed design 2 supported by anysuitable supporting surface IS. The adhesive I8 is then placed on thetop of the stencil and is pressed through the holes in the stencil bymeans of a squeegee 20 which is adapted to move over the perforatedscreen I4. As previously stated, the movement of the squeegee may beaccomplished either by manual or mechanical means. A plan view of thisoperation is illustrated in Figure 6, showing the appearance of thestencil I4 after a portion of the pressure sensitive adhesive l8 hasbeen applied by squeegee 20.

As shown in Figure 8, a number of displays may be printed at the sametime in a single printing operation and then separated from each otherby die cutting along. lines 22. In this event, the adhesive pattern maybe applied as shown in Figure 9 so that the die cuts pass through thesquares of adhesive 24 thereby insuring that the adhesive runs to themargins. Otherwise, if the die cut ran through the spaces between theadhesive the margin would be uncoated and the display might tend to turnup or peel off from its supporting surface; It will be understood thatthe printed design is preferably dried prior to the application of theadhesive.

According to the preferred embodiment of the invention, certain of theholes or perforations in The product thus obtained will have.

the stencil are stopped up so that no adhesive is applied in the areas26 which form the corner portions of the display when it is die cut. Theadhesive coating on the display material thus formed is illustrated inFigure 10, in which the corner portions 28, 30, 32 and 34 contain noadhesive. This makes it possible to strip holland cloth or othercovering material from the adhesive easily without injuring the basematerial. One or all of the corner portions of the adhesively coatedside of the base material may be freeof adhesive- The patternsillustrated in Figures 11 and 12 represent modifications of theinvention. In Figure 11, the adhesive pattern consists of spacedstaggered circular spots. In Figure 12, the adhesive pattern consists ofdiagonally disposed squares and triangles so, arranged that a horizontalor vertical die cut, or series of die cuts necessarily produces adisplay in which adhesive lies along the margin. This latter arrangementis especially useful where a number of displays are made at once, asdescribed with reference to Figures 8 and 9.

It will be observed that the adhesive-free areas or spaces in every caseconnect with one or more marginal spaces thus permitting entrapped airto escape and avoiding bulges in the display.

It will be understood that certain variations may be made in the methoddescribed without departing from the invention. For example, the type ofpressure sensitive adhesive employed is subject to wide variation.v Anexcellent type of pressure sensitive adhesive for the practice of thisinvention is one made from a pure crepe or gum rubber base which hasbeen thinned with a slow drying rubber solvent which may contain adiluent. The rubber base may be dissolved in the solvent toformasolution that is very viscous.

. The rubber composition itself, which is used for making the pressuresensitive adhesive, does not form a part of this invention because thereare many and varied types ofv pressure sensitive adhesives that could beemployed. The pressure sensitive adhesive need. not be made from arubber base but may be made from combinations of various kinds of resinseither alone or in conjunction with a rubber base.

When the base material is a rubber impregnated fibrous material such asLexide the pressure sensitive adhesive may ordinarily be applieddirectly, although if desired, an intermediate anchor coat of some othertype of material such as a rubber cement may be applied. Where the basematerial is a paper, an anchor coat of rubber cement is especiallydesirable.

The term pressure sensitive adhesive as employed herein is intended tocover any type of adhesive which derives its adhesive action merely frompressure and which is capable of being removed from an object to whichit is fastened likewise by pressure in the opposite direction. Thechoice of the adhesive should be such that the adhesive will cling to afibrous material of the type used as a base material herein morestrongly than to a plane non-fibrous surface. Since this property ischaracteristic of most pressure sensitive adhesives, the proper choiceof' an adhesive will readily be recognized by those skilled in the art.Likewise, it will be recognized that the adhesive should be one whichcan be applied in the form of a solvent solution of such viscosity thatit is capable ofbeing passed through the-perforations or holes in thestencil. Here again the proper choice of an adhesive may readily beascertained by one skilled in the art. After being applied at least aportion of the solvent in the adhesive is removed by drying orevaporation.

In practicing the invention the area of the base material covered byadhesive is ordinarily from about 30% to about 90% of the total area andthus there is a considerable saving in the amount of adhesive requiredas compared to methods heretofore used where the entire rear surface ofthe base material was covered by the adhesive. The perforations in themetal screen of the stencil may likewise be varied from, say, 4perforations per square inch to as high as 100 perforations per squareinch, depending upon the adhesive power of the pressure sensitiveadhesive, the thickness of the film and the spacing desired in theadhesive pattern. It is ordinarily preferable to employ a metal stencilhaving uniform perforations from about 4 to about perforations to theinch.

The adhesive pattern may be placed either on the face of the design orthe back of the base material, or on both the face and back. If theadhesive is placed on the face it may be colored and placed in certainportion of the design of the same color so as to appear as part of thedesign. If the adhesive is transparent it may be spot coated entirelyover the design. For some purposes, it is desirable to apply theadhesive pattern only to the border or marginal portions of the back orface of the material, leaving the interior portion adhesive-free. Thus,in making truck signs it is often preferable to spot coat or stencil thepressure sensitive adhesive along the rear border of the sign leavingthe interior portion uncoated.

The term stencil as employed herein refers to'a thin sheet or plate inwhich a pattern is cut by means of spaces or dots and through which apressure sensitive material applied to the surface penetrates to asurface beneath. The term stenciling is used herein to describe themethod by Which the pressure sensitive adhesive is applied using astencil. An outstanding feature of this invention resides in the factthat stenciling apparatus is normally available in most manufacturingplants where printed designs or displays in color are made and hence,the use of this invention enables a manufacturer of poster displays ofthe character herein described to apply the adhesive coating in his ownplant after the display has been printed rather than being compelled tobuy a roll of pre-coated material as has heretofore been the practice.

The invention is particularly important in the manufacture ofadvertising posters, placards or displays of the type described whichare of relatively large area. The use of a pattern of adhesive withinterconnecting spaces makes it possible to apply such displays to asupporting surface without trapping air and causing bulges. Theinvention is particularly important also in making advertising displays,posters or the like whether large or small from a base material ofpaper. The provision of interconnecting passages in the adhesive patternmakes it possible to produce displays, placards and the. like at'a lowercost and tends to prevent distortion, warpage and shrinkage of the paperand of the design thereon.

rthermore, as previously pointed out, one of the preferred embodimentsof the invention wherein a corner is left free of adhesive is especiallyimportant when the base material is paper because it is thereby possibleto separate the base material containing the adhesive coating 75;

from-holland cloth or other protective coating or from a supportingsurface without splitting the paper.

Having thus described the invention, what we claim as new and desire tosecure by Letters Patent of the United States is:

1. A poster advertising material of the character described comprising abase material of substantial area in all directions bearing printedadvertising indicia and having on one surface of said base material apattern of pressure sensitive adhesive with interconnecting spacesthroughout the adhesive pattern and with adhesive areas andadhesive-free spaces along the margins of the material such that the aircan escape through said adhesive-free spaces when the material isapplied thereby preventing air pockets and bulges, said interconnectedspaces communicating with the margins of said material.

2. A poster advertising medium of the character described comprising aflexible, unified base material of substantial area in all directionshaving a printed design on one surface thereof and a pattern of pressuresensitive adhesive on the other surface thereof with interconnectingspaces throughout said pattern so arranged as to substantially preventthe formation of air pockets when the material is applied to anothersurface and with adhesive areas along the margins and areas free ofadhesive at corner portions of said material, and a covering materialover said adhesive also covering the spaces fre of adhesive and capableof being stripped therefrom starting at the adhesive-free cornerportions, said interconnected spaces communicating with the marins ofsaid materiaL,

3. A poster advertising material of the character described comprising abase material of substantial area in all directions bearing a printedadvertising indicia having thereon a predetermined pattern of pressuresensitive adhesive with interconnecting spaces in said adhesive patternin sufficient number and so arranged as to substantially prevent theformation of air pockets when said material is applied, said spacesinterconnecting with the margins'of said material and an area free ofadhesive at a corner portion of said material,

4. A poster advertising medium of the character described comprising abase material of substantial area in all directions consistingsubstantially of paper bearing a printed advertising indicia and havingthereon a coating of pressure sensitive adhesive with interconnectingspaces in the adhesive pattern in sufficient number and so arranged asto substantially prevent the formation of air pockets when the materialis posted, said spaces inter-connecting with marginal portions ofsaid'base material, and an area free of adhesive at a corner portion ofsaid material.

5. A poster advertising material of the character described comprising apaper base material of substantial area in all directions bearing aprinted advertising indicia on one surface and having on the othersurface a predetermined pattern of pressure sensitive adhesive withinter connecting passages in the adhesive pattern which are free ofadhesive, said adhesive being placed at intervals along the margins ofsaid material with said passages extending therethrough to said margins,and areas free of adhesive at corner portions of the adhesively coatedside of said material.

CASPAR, F.v ENGERT. ALBERT G. SCHMIDT.

